Interactive decision-tree builder

Construct fast-and-frugal decision trees against built-in or uploaded datasets. Define nodes, visualize the tree, and inspect classification performance.

Reasoning under hidden information

Play the classic capture-the-flag game against a bot that has to infer what your pieces are. It maintains a belief over every unseen piece, updates it only from what a human opponent could observe, and searches from there. Three difficulties — none of them cheat.

A meditative journey through pools of dots

Move your mouse through drifting constellations of dots and watch them pulse away and settle back. Move too fast and the light sinks. Hidden fireworks, a sky of distant stars, and a black hole to the next pool. Best with sound on.

Classic problems, pixel-art games

A retro-styled arcade of interactive games exploring classic problems in statistics and decision science, from the Birthday Problem to the Secretary Problem.